International Workshop on Future Linear Colliders, LCWS2024

A CP violating top-Higgs coupling with SMEFT in the Feynman-Diagram gauge

8 Jul 2024, 17:30

2h

Foyer (Ito International Research Center)

Poster (in person) BSM, Global Interpretations Posters

Speaker

Ya-Juan Zheng

Description

We calculate the cross section for the process ${\mu }^{-}{\mu }^{+}\to {\nu }_{\mu }{\overline{\nu }}_{\mu }t\overline{t}H$ with complex top Yukawa coupling, which can be obtained by adding a gauge invariant dimension-6 operator to the Standard Model (SM) Lagrangian. The Feynman-Diagram (FD) gauge and the unitary (U) gauge amplitudes give exactly the same cross section, and subtle gauge theory cancellation among diagrams in the U gauge at high energies is absent in the FD gauge, as has been observed for various SM processes. In addition, we find that the total cross sections at high energies are dominated by a single, or a set of non-vanishing Feynman amplitudes with the higher dimensional vertices in the FD gauge.

Presentation materials

LCWS2024_0708_zheng.pdf

Peer reviewing

Paper

Accepted on 23 Nov 2024 by Junping Tian

0LCWS2_FD_revised1122.pdf